1. Field of the Invention
The invention relates to a method for the manufacture of decorative laminate panels. More particularly, the invention relates to a method for compound injection molding decorative laminate flooring planks and planks manufactured in accordance with the present method.
2. Description of the Prior Art
Decorative laminate panels, and particularly, decorative laminate flooring planks, are commonly manufactured in a linear manner. That is, the various components move through an extensive processing line where the various components are bound, cut, sized, shaped, boxed and shipped.
The first step in the linear manufacture of decorative laminate flooring is combining the components of the flooring planks. Specifically, the cores, backing layers and decorative panels are continuously fed and assembled into large decorative panels requiring substantial additional processing before the final product is ready for shipping and use. Once a large decorative panel is completed and inspected, it is conveyed to a processing line where it is machined into a predetermined number of flooring planks. Finally, the finished flooring planks are packaged and palletized for shipping.
It should be understood that the process described herein is designed to be continuous. As such, a breakdown occurring at any point in the line results in the shutdown of the entire processing line until such a time that the problem is corrected. The size of the problem is generally irrelevant and the line must be shut down whether a belt is misaligned or the entire control system goes down.
The use of line processing further limits production capabilities, and necessitates a substantial investment in updating or replacing equipment segments within a processing line once the capacity of a given equipment segment reaches its production limit. For example, if a packaging segment in a flooring plank processing line is capable of packaging 36 boxes of 8 planks per hour, the remainder of the line is limited to this capacity regardless of whether other equipment segments are capable of a greater output. The replacement or updating of equipment segments to raise the overall line output may continue until such a time that the size of the processing line exceeds the allotted space. The entire processing line must then be moved to a larger space or replaced with an entirely new line. Manufacturers, therefore, attempt to maximize the production capabilities of an existing line before investing substantial sums of money into the creation of a new processing line.
However, increased speed is not always an answer to the need for increased production. When a processing line is pushed to its limits, it is more likely to break down, resulting in down time. In addition, where a processing line is operating at maximum capacity, for example, 100 flooring planks per minute, errors in processing result in the disposal of all items processed during a given time period. When this occurs, 1,500 planks would necessarily be thrown away where planks were being manufactured in error for a period of only 15 minutes.
In accordance with one known production line, the large decorative panels are formed as approximately 1.22 m×2.44 m sheets. Each sheet is then cut into a predetermined number of flooring planks. The edge detail of each plank is then machined and the planks are packaged for shipping.
Extensive and expensive cutting tools are used in converting these large panels into multiple planks, as well as in machining the required edge profile into the flooring planks. The extensive use of cutting tools adds substantial time and expense to the manufacturing process. For example, the positioning and wear status of the cutting tools is continuously monitored to ensure the highest quality in the resulting flooring planks. In addition, the cutting tools are preferably diamond tipped and maintenance of these diamond tipped cutting tools adds substantial expense to the manufacturing process.
In addition to the cost and maintenance problems associated with the use of conventional cutting tools in the manufacture of flooring planks, the use of cutting tools limits the possible edge profiles that maybe formed on the flooring planks. These limitations in turn restrict the possible designs which might be used to improve the functionality, repairability and installability of flooring planks.
Current machining techniques used in forming desired edge profiles require that substantial portions of the core, decorative laminate wear surface and backer laminate be machined away. This generates substantial and undesirable waste.
As mentioned above, conventional flooring planks are manufactured with a decorative laminate wear surface, a backing layer and a core positioned between the wear surface and the backing layer. The use of current manufacturing techniques severely limits possible variations which might improve the structural characteristics of the flooring planks.
For example, the core or substrate materials commonly used in conventional flooring planks are wood-based and, therefore, susceptible to the effects of moisture. Moisture renders wood-based substrates highly susceptible to warping, shrinkage, and separation between the decorative laminate wear surface, backer layer and the core. Since current flooring plank manufacturing techniques have been developed to primarily handle wood-based core materials, their adaptation for manufacturing flooring planks utilizing alternate, waterproof, core materials is thought to be impractical.
In addition to the water damage to which wood-based flooring planks are susceptible, the use of wood-based core materials substantially extends the time required for producing flooring planks. Before a core material may enter the processing line, the core material, for example, medium density fiberboard, must sit in a controlled environment for a period of approximately 24 hours to 72 hours to ensure proper temperature equilibration. Similarly, once the wear surface and backing layer are bonded to the core, and the flooring plank is formed, the finished flooring plank must further sit and equilibrate for an additional 24 hours to 72 hours. This final sitting period allows for the dissipation of stresses from the formed panel.
The extended sitting periods required in the manufacture of decorative laminate flooring planks necessitate that substantial storage space be provided. The extended sitting periods further leave the core materials and finished flooring planks susceptible to damage during the time in which they are required to sit. For example, core sheets are often permanently bent or warped during storage and must be thrown away.
Damage to the formed panels and/or planks is also encountered as a result of the many steps involved in the production thereof. As those skilled in the art will certainly appreciate, the components of the panel are moved many times during production of a flooring plank and each time the panel, or the components thereof, are moved, there is a chance that damage will occur.
The shortcomings of traditional manufacturing processes used in the production of decorative laminate flooring planks highlight the need for a new approach in the manufacture of decorative laminate flooring planks, as well as other decorative laminate products. The present invention provides a new and innovative approach to the manufacture of decorative laminate flooring planks and other related decorative laminate products.